ATVs and snowmobiles are very popular and special trails have been developed for practitioners of that activity. In order to maintain the trail however, there is a need for grooming implements.
Although a number of devices are used for that task, they are often simply repurposing existing devices to perform the task. For example, the prior art contains machinery use for working soil while other prior art uses similar soil working implements adapted for work on snow, such as substituting skis for wheels.
U.S. Pat. No. 1,026,552 hows an early example of a grooming device for skiers.
U.S. Pat. No. 3,915,239 shows a device having multiple articulated frames as well as a compactor at the end to compact the snow.
The use of angled plows or graters used for redirecting soil or snow is also knows in the art.
What is not well known, except perhaps for U.S. Pat. No. 4,898,247 is the use of the inclination of the graters, or blades to carve deeper on one side. U.S. Pat. No. 4,898,247 is for use on soil so it does not require a compactor and as such uses a leveling system based on actions from the rear wheels.
Because working on soil is different than working on snow, for example, soil needs to be fluffed and aerated in order to facilitate seeding and plant growth, whereas for snow trails, the snow needs to be compacted so as to remove the air and pack it solid. For this reason a device needs more than just obvious modifications in order to be adapted from soil use to snow use, and vice versa.